Recipes vary from those having equal parts of each ingredient to those that use a ratio of 3 to 2 of whisky to wine.
A common recipe is to take 45 millilitres (1+1⁄2 imperial fluid ounces) Scotch whisky and 45 mL (1+1⁄2 imp fl oz) green ginger wine.
[1] Pour both of the ingredients into a wine goblet with no ice.
The invention of it, and its name, is attributed to Colonel Hector MacDonald, who devised it during the days of the British Raj in India.
Apparently, golfers drank whisky macs to ward off the cold after a chilly round on the links.